Controlling the operation of numbering machines

ABSTRACT

A control system is described which assembles digital data representing the operations to be performed by the devices (the printed material consisting of the digits corresponding to the identification numbers which are presented by numbering machines which are incremented as the imprinter executes its successive document feeding cycles). A channel is provided for each device, which is responsive to the data and through which the data is advanced so as to operate the device in accordance therewith. A check digit printing device is operated by way of its associated channels so as to present the check digit corresponding to the identification number to be printed and enable corresponding identification numbers and check digits to be printed simultaneously at different locations on a multiplicity of different documents.

The present invention relates to control systems for operating amultiplicity of digital data responsive devices to perform likeoperations in selected time sequence governed by the cyclical operationof the devices.

The invention is especially suitable for use with imprinters which printidentification numbers and corresponding check digits on documents wherea multiplicity of such numbers and digits are required in differentlocations on the same document. The invention is applicable wherever amultiplicity of digitally driven mechanisms must accept the same dataand yet provide different operations in response to the data atdifferent times, with the operations being the same with respect to anoperation receiving element so as to have the same effect as if alloperations were performed on that element simultaneously.

Various systems and imprinting machines have been designed for printingidentification numbers and check digits on documents as they are printedon the machine or on forms which are fed through the machine. The checkdigits bear a certain mathematical relationship to the identificationnumber as may be computed by weighted modulus numbering. Theidentification numbers and check digits may be printed so as to be readby magnet ink character recognition devices, optical characterrecognition devices, or in numerals understandable by the key punchoperator who enters data from the document into a computerizedaccounting machine. In the event that the document number is incorrectlyentered as may be verified by the computerized accounting machine, thedata from that document is rejected by the accounting machine. Varioustypes of machines for generating and printing identification numbers andcheck digits and for verifying the digits are commercially available andreference may be had to U.S. Pat. Nos. 3,650,205 issued Mar. 21, 1972and 3,833,795 issued Sept. 3, 1974.

Conflicting requirements, as printing a multiplicity of identificationnumbers on the same document, while printing the documents at highspeed, say hundreds of documents per minute, have retarded thedevelopment and introduction of document verification numbering into thecommercial market. The document number must be printed in severallocations on the document; for example, in magnetic ink in one place,and in arabic numerals which can be read by the operator in otherplaces, say on a voucher section and official section of the samedocument. The identification number is generated by numbering machinesusually having several number wheels mounted on a shaft with gearingbetween the wheels so that the numbers increment on each machine cycle.The documents are fed so that successive documents appear under thenumbering machines for printing after each cycle. The check digits ofthe document numbers corresponding to the identification numbers aregenerated by a computer.

The expense of a computer militates against the use of separatecomputers for each of the multiplicity of document numbers required foreach document. In short, it is impractical to utilize three computers inthe case where three document numbers are to be printed on the samedocument.

Moreover, each document number although in somewhat different format, asfor magnetic ink character recognition, optical character recognition,or in arabic numbers, is identical. However, the numbering machineswhich present the document numbers for printing occupy too much space toallow for the location of a multiplicity of such machines in registrywith each document. Nevertheless, the document printing speeds desiredare too high to permit movement of the document, say laterally, withrespect to the numbering machines, or to allow for several passes of thedocuments through the machine so that different numbers can be printedin different passes. In addition, the timing of the operation of themachine which presents the identification number and check digits mustbe synchronous with the cyclic operation of the imprinter, otherwise thedocument numbers may not appear in proper registry with the documents orthe numbers may be cut off in whole or in part so as to be illegible.The computer which generates the data words corresponding to the checkdigits and the printing machine, are independent of each other withrespect to their separate operating speeds. Unless the check digitprinter is operated in proper synchronism with the cyclic operation ofthe machine, the check digit which is printed may not correspond to theidentification number. Then the document numbers will be incorrect suchthat upon verification, the information entered from the document willbe rejected.

Accordingly, it is an object of the present invention to provide animproved system for controlling delivery of data from a data source to aplurality of data responsive devices, such as the check digit printersof a multiple document number printing machine, so that a multiplicityof operation occurs at the same time, but in different time relationshipwith respect to each other such that an operation receiving element suchas a document, receives operations, such as the printing of documentnumbers, which are all alike.

It is another object of the present invention to provide an improvedsystem for controlling the printing of document numbers which enables amultiplicity of numbers to be printed on a single document at high speednotwithstanding that the mechanisms for printing cannot be located inregistration with the same document at the same time.

It is a still further object of the present invention to provide animproved system for controlling a document number printer which acceptsdata corresponding to the check digits of the document number eventhough such data may be generated asynchronously by a computerindependent of the document number printer.

It is a still further object of the present invention to provide animproved system for controlling a document number printer which isadapted to print a multiplicity of document numbers on each document asit is fed through the printer which makes extensive use of circuitrycommon to the devices which control the printing of each of themultiplicity of numbers and is of a design which is economical tomanufacture.

Briefly described, a system for controlling the operation of amultiplicity of devices to perform operations repetitively withdifferent ones of the devices performing identical operations inselected time sequence, such as the printing of a multiplicity ofdocument numbers including identification numbers and correspondingcheck digits on each document of a succession of documents which are fedthrough a printing machine, which embodies the invention, makes use of adata source which provides sequential data words which define theoperations of the devices. This data source may be a computer whichoutputs digital words representing the check digits corresponding tosuccessive identification numbers which are to be printed in multiple onsuccessive documents as they are fed through the printing machine. Amultiplicity of cyclically operative means is separately associated withthe devices. These means produce repetitive first timing signals fortiming the operation of the one of the devices which is associatedtherewith, for example the check digit printer for the identificationnumbering machine which prints the identification number correspondingto that check digit. One of the timing signals is selected to provide arepetitive lead timing signal which is synchronous therewith and, in thecase of the document numbering machine, is synchronous with the printingcycles during which successive documents are fed into registration withthe numbering machine and have the document numbers printed thereon. Amultiplicity of channels are each output coupled to a different one ofthe devices and all of the channels are input coupled to the datasource. An interface unit may be provided between the data source andthe channels having a first in - first out memory device whichcooperates with the data source to store a succession of data words insequential order. The data source then may operate asynchronously withrespect to the printing machine under the control of the system. Eachchannel includes a multiplicity of registers for storing a plurality ofdata words in places which are located in sequential order in eachregister and a multiplicity of converting means which convert the datawords into device operations corresponding thereto. Under the control ofthe lead timing signal the data words are read out of the data source orthe interface unit which is coupled thereto into the registers andadvanced between the stages of the registers. In the control systemaddresses are generated for outputting data words which are stored indifferent places in the registers of different channels to theconverting means for their channels. The converting means are alsoenabled by the timing signals for the devices which receive operatingsignals from the converting means. Accordingly, the devices are alloperated synchronously. In the case of the printing machine where thedevices are the check number printers for the check digits for each ofthe multiplicity of identification numbers, the check digits are setinto printing position in response to the data words in synchronism withthe document feeding and printing cycles of the machine. The checkdigits and the identification numbers are then printed in properregistry. Each of the multiplicity of numbers may be printed on adifferent document, spaced apart by one or more intervening documents.By virtue of the addressing, the data representing the check digits maybe different data and check digits printed may be different. However,these different digits are printed on different documents and when thedocuments arrive at the devices for printing each of the multiplicity ofidentification numbers, the identification numbers will be the same.Accordingly, each document will have the same identification numbersprinted in different locations thereon while the printing machine isbeing operated at its maximum speed.

The foregoing and other objects, features and advantages of theinvention as well as a presently preferred embodiment thereof will bemore apparent from a reading of the following description in connectionwith the accompanying drawings in which:

FIG. 1 is a schematic diagram illustrating the relative location ofdocuments which are being printed on a printing machine and the printingheads which perform the printing operations when these printing headsare operated by a control system embodying the invention;

FIG. 2 is a schematic diagram illustrating three printing heads forprinting document numbers including identification numbers and checkdigits which is adapted to operate with a control system embodying theinvention; and

FIGS. 3A and B is a block diagram illustrating the control system inaccordance with the preferred embodiment of the invention which isadapted to operate with a multiplicity of printing heads such as thethree printing heads illustrated in FIG. 2.

Referring more particularly to FIG. 1, there is shown a series ofdocuments such as checks 10 which are provided successively on acontinuous form. The individual checks 10 are separated by perforations12 so that they can be torn apart from the continuous form. The formitself has drive holes 14 and 16 along its edges so that it can bedriven through a computer printer which may print the payee, the amountof the check, other information on the check, and on the check stubs 18which are associated with the check. In a document number printingmachine a multiplicity of document numbers, in this case three numbers,which are identical to each other are printed on each document. In thecase of checks as illustrated, one of these numbers is printed on thestubs 18 and two document numbers are printed on the checks. The numberson the voucher and in the upper righthand corner of the check may bearabic numerals while the number in the lower lefthand corner of eachcheck may be a magnetic ink format. In the example given, only fourdigits are shown. The digit in the lowest order digit position, i.e., atthe righthand end of the number, is the check digit. The remainingdigits constitute the identification number. While only three digits inthe identification number are shown, identification numbers may havemany more digits. In the illustrated example, the four highest orderdigits are 1101. These digits have not been shown to simplify theillustration. The identification number portions of each document numberincrease in value by increments of 1 and these numbers may be printed byprinting heads, also referred to as numbering machines, which arediscussed in more detail hereinafter in connection with FIG. 2. Thecheck digits corresponding to these numbers are computer generated andhave values depending upon the identification number which forms thedocument number therewith as by the weighted modulus numberingtechnique. The printing heads PH-1, PH-2 and PH-3 are too large to beassembled together in the space of a single check which, for example,may be only three inches in width. This three-inch distance is calledthe cycle distance since the checks must be fed the cycle distance topresent successive checks to the printing heads.

In order to allow sufficient space for the printing heads, they areassociated with every third document, and in this illustrative case arenine inches apart along the direction in which the documents are fed,which direction is indicated by the arrow 20. The imprinting of threeidentification numbers in three different positions on three spaceddocuments is carried out simultaneously in the machine which prints thedocument numbers. The numbering machines which print the identificationnumbers in the three different locations are set to print numbers threeincrements apart. As shown in FIG. 1, PH-1 prints the identificationnumber 139, PH-2 prints 136, and PH-3 prints 133. Thus, when the checkis fed three document cycle distances, the second print head PH-2 willhave advanced to the same number as printed on the document by the firstprint head PH-1. This is illustrated in the drawing by theidentification number 136 which was printed by PH-1 three documentcycles prior to the cycle on which the check has reached the position ofPH-2. Similarly, when the same check reaches the third print head PH-3,PH-3 will have advanced to the same identification number which wasprinted on the check by both PH-1 and PH-2. As the checks pass PH-3 theywill have all three document numbers identically the same and printedthereon in different locations. High speed printing of the documentnumbers is thereby effected in the document number printing machine.

The printing of the check digit is under the control of the systemprovided by the invention.

Consider first the numbering machines for printing the identificationnumbers and the associated device for printing the check digits. All arecontained in the same print head as shown in FIG. 2. Consider the firstprint head PH-1 which is typical of the three print heads. The digits ofthe identification number are type faces on wheels 22, 24, 26 and 28.The wheels 22, 24 and 26 are part of the numbering machine. These aremounted on the same shaft 30. Three numbering machine wheels are shownto simplify the illustration. One wheel is provided for each digit withthe lower order digit wheels connected to the higher order wheels, as byratchet and pawl mechanisms or gearing 32 and 34 so that thesuccessively higher digits increment each time the digit of lower orderthereto increments through "0." In practice it is preferable to set thedigits manually with a pick. However, the individual digit wheels 22, 24and 26 may have ratchets 36, 38 and 40 which may be engaged by pawls 42,44 and 46. These pawls may be operated electrically by solenoids 48, 50and 52 which may receive, from a suitable source, set pulses indicatedas SET 1-1, SET 1-2 and SET 1-3 for print head PH-1. By pulsing thesolenoids with the SET inputs, the ratchets may be advanced to set thedigits of the identification numbers at the start of numberingoperations.

The shaft 30 is also keyed to a disc 54 which may be of non-magneticmaterial, such as aluminum. A drive puck 56 and a station drive disc 58are also connected to the shaft 30. The aluminum disc 54 has a magnet60, which may be a cylindrical stub permanent magnet, embedded therein.This magnet 60 is associated with a Hall effect proximity switch 62which produces a pulse each time the magnet 60 passes the Hall effectproximity switch. This switch is referred to as HEPS and its outputpulse as HEPS-1. This output pulse serves as a timing signal in thecontrol system.

Each of the digit wheels 22, 24, 26 and 28 prints when a hammer for theentire numbering machine (consisting of multiple wheels) is actuated orfired. The hammer fires each printing cycle. Hammer firing ismechanically tied to the station drive disc 58 rotation and as the disc58 is adjusted, so is hammer firing time. The Hall effect proximityswitches suitably provide these output signals just after the hammerfires to allow maximum time for stepper motors to actuate, whichprovides high speed operation. The timing pulses HEPS-1 to 3 areinitiated by the passage of the magnet 60 in proximity with the Halleffect proximity switches directly after their firings, i.e., afterprinting. If for example, the document numbers are desired to be printedat different locations widthwise across the document (viz, in thedirection of feedings 20) the digit printing wheels may be adjustedangularly with respect to the disc 54 so that the digit to be printed ispresented to the hammers when the location on the check which is toreceive the number is in registry therewith. The station drive disc 58may for example be adjustable 360° so as to rotate the aluminum disc 54and the shaft 30 with respect to the puck 56. The puck 56 and similarpucks 64 and 68 on the other print heads PH-2 and PH-3 are driventogether from the imprinter drive by timing belts 66, 69 and 70. Thetiming belts cause the numbering wheels to increment or cycle each timethe form is fed through a cycle distance, as shown in FIG. 1. This cycledistance is also the repeat length of the form since different formspresent themselves repeatedly at the print heads when the print headsrotate through a cycle (360°). The print heads are therefore cyclicallyoperated devices.

The check digit numbering wheel 28 is driven through gearing 72 by astepper motor 74 so as to present the proper check digit for eachidentification number as that number increments cyclically. The steppermotor 74 is driven by stepping pulses and the rotation of the steppermotor shaft 76 and the consequent rotation of the check digit printwheel 28 is determined by the number of step pulses which are applied tothe wheel each cycle of rotation of the shaft 30 (i.e., eachidentification number cycle). Preferably the stepper motor includeslogic for steering the stepper pulses so as to rotate the shaft eitherclockwise or counterclockwise. Then the rate at which the check digitsare advanced into printing position is accellerated. Accordingly aclockwise, counterclockwise command CW/CCW is applied together with thestep pulses STPULSE to the stepper motor 74. The step pulses STPULSE forthe stepper motor 74 or stepper motors 78 and 80 which drives the checkdigit wheels of the second and third print heads PH-2 and PH-3 areprovided by the control system.

The control system is illustrated in FIG. 3. A data source 82 such as acomputer, generates, as in accordance with the weighted modulusnumbering technique, successive data items (four-bit digital words) ondata lines D-1, D-2, D-3 and D-4 for each bit of the words. The firstdata word which is generated corresponds to the first identificationnumber to which the print head which prints first is set. This firstprinting print head is PH-1 in the example given in FIG. 1. The datawords which are generated successively after the first data wordcorresponds to the check digit for the next higher and then the othersuccessively higher identification numbers. A list of identificationnumbers and their corresponding check digits may be printed out by aprinter associated with the computer 82 so as to verify the printing ofthe correct document numbers when the document number printing machineis set up initially for operation. Thereafter it may be desirable tocompare the document numbers with the list only infrequently, say everyseveral hundred documents. The control system also includes a keyboardconsole 84 which contains control switches. All of the other componentsof the control system are internal thereto.

A data interface 86 having interface control logic 88 and a memory 90for storing several, say 16 consecutive data words, is contained in theinterface 86. The data lines D-1 to D-4 present the successive datawords to the memory 90 when the interface control logic 86 outputs a FLGcommand to the computer 82 indicating that the memory 90 has received adata word and an empty position is available to receive a successivedata word. When the next data word is available, the computer outputs aCTL command to the logic 88 which enables the memory 90 to accept thenext data word. In this manner the memory 90, at the outset of printingoperations, quickly is loaded with a sequence of data words. The memory90 itself is desirably a first infirst out memory such as the integratedcircuit device manufactured by Fairchild Semiconductor, their Part No.9403. The memory 90 and the data interface 86 enables the computer 82 tooperate asynchronously, i.e., at different times than the control systemand out of synchronism with the cyclic operation of the printing machineand the printing of the document numbers.

The timing signals from the Hall effect proximity switches HEPS-1,HEPS-2 and HEPS-3 (see FIG. 2) are applied to input data control logic92 which contains sampling and gating circuits. A timing pulse generator94, as may contain a clock pulse oscillator and dividers, applies pulsesat a sampling rate which will produce at least two complete samplingperiods within the narrowest expected pulse from the HEPS lines (whenthe printing machine is operating at its full speed). In response to thesampling pulses the HEPS timing signals are translated into three timingpulses which are substantially free of noise. These pulses are outputtedon channel start lines labeled CH1START, CH2START, and CH3START. One ofthe timing pulses is selected to be the lead pulse. The keyboard 84switches include a latching switch which makes the selection andoperates gates in the control logic 92. The selection commands areapplied to the control logic 92 by way of select lead channel commandlines from the keyboard switches 84. The term "channel" is used todenote that the lead timing signal LS which is outputted by the controllogic 92 is derived from the HEPS timing signal for the one of the printheads PH-1, PH-2 or PH-3, which is operated by one of three channels 96,98 and 100 of the control system which has been selected as the leadchannel. Two lead channel timing signals are outputted by the controllogic. They are timing pulses on a lead signal line LS and readoutstrobe pulses ROSTRB which are slightly delayed, as by one-shot logic inthe control logic 92, which is denoted by the ROSTRB output line.

Each of the channels 96, 98 and 100 is associated with a different oneof the print heads. Channel 1 which is identified by reference numeral96 is associated with PH-1; channel 2 (98) with PH-2; and channel 3(100) with PH-3. Each of the channels has the data lines D-1, D-2, D-3and D-4 from the data interface 86 connected thereto such that the datafrom the memory 90 is applied simultaneously to the input of eachchannel. Each channel contains a buffer memory which functions as adelay buffer for the data. The buffer memory may be a shift registerwhich is four-bits wide by sixteen words long and thus provides storagefor up to sixteen words. As will become apparent as the descriptionproceeds, each stage of the memory corresponds to a time delay of onecycle of the printing machine such that the buffer memories allow for amaximum of sixteen cycles delay. If less delay is required, memories ofshorter length or not every one of the sixteen stages may be utilized.

Each of the channels also includes a stepper motor control whichconverts the data from the memory of its channel into a mechanicaldisplacement of the stepper motor. The stepper motor controls respond tothe four-bit data words and develop a gate of duration corresponding tothe value of the word. The stepper motor control also includes a memoryfor storing successive data words and arithmetic logic for determiningthe sense of the difference between the values so as to derive adirection command for the shortest angular rotation of the stepper motorto the angular position for each data word. Instead the data words maybe decoded by a decoder in the stepper motor controls to obtain theCW/CCW commands. The timing pulse generator 94 provides a stepper motorcompatible rate (ADV pulses) as well as the sampling rate describedpreviously. When the stepper motor gate is open, this compatible ratefrom the timing pulse generator 94 is outputted on the stepping pulseline (STPULSE) thereof. The direction command is simultaneouslyoutputted on the CW/CCW line of the stepper motor control. The steppermotor control does not output the STPULSE pulses or the CW/CCW commanduntil enabled by the CH1START, CH2START, or CH3START, pulse for thechannel or the stepper motor which is applied to the stepper motorcontrols from the input data control logic 92. Each channel alsoreceives channel ON commands CH-1-ON, CH-2-ON and CH-3-ON from thekeyboard switches 84. Each channel may be selectively operated from thekeyboard 84 which either provides or does not provide these channel ONcommands depending upon the operation of the keyboard.

Provision is also made for manual stepping of the motors which is usedduring initial set-up operations. The keyboard switches include inchcommand switches which provide commands on an INCH STEP line andINCHCMD-CH-1, INCHCMD-CH-2, and INCHCMD-CH-3 lines. The manual controlis enabled from the keyboard by activating an INCH-ON line. The inchcommand line for the channel to be set is then activated which operatesgates in the advance control logic 102 so as to enable inch step pulsesgenerated by an inch step keyboard switch to be outputted on one of theinch output lines from the advance control logic 102; INCH-1, INCH-2 andINCH-3. These pulses are applied directly through the stepper motorcontrol for their channel to operate the stepper motors so as to rotatethe check digit print wheels thereof to the desired digit positions.

In order to control the timing of the check digits relative to eachother and enable different digits to be printed at the same time whichcorrespond to different identification numbers and yet have all of theidentification numbers and check digits on the same document come out tobe the same, the buffer memories for each of the channels are separatelyaddressed by a cycle delay timer 104. This timer for the sake ofsimplicity provides addresses DEL2ADR and DEL3ADR on address lines whichare connected to the channel 2 and channel 3 buffer memoriesrespectively. The channel 1 buffer memory is not addressed and the datafrom a predetermined stage thereof, say the first stage, is continuallyderived. In order to address the other channel memories, address numbergenerating counters Counter-2 and Counter-3 in the delay timer 104 areused. These address counters indicate the stage of the shift registerwhich is to be read out. In this implementation described, the furtherdown the shift register string from the first stage, the more the delaywith respect to channel 1. The delay is set by the operator from thekeyboard at the proper time by activating digital switches PS-2 and PS-3to the counters. The counters count the LS pulses until the switchesPS-2 and PS-3 are activated by the operator. Different delays toaccommodate different document widths and disposition of print heads canreadily be accomplished so as to enable flexibility of use of thedocument number printer with various types of documents and forms.

At the start of operation a start/set switch in the keyboard 84 isactuated and provides a start/step command SST which clears the delaytimer counters and enables the FIFO memory 90 to fill with data. Asmentioned above, when the system is turned on and is running, the buffermemories in the channels begin to accept data. The LS pulses clock datainto the channel buffers and together with the PS commands then set thecounters in the delay timer 104 and the buffer memories are addressedwith the proper delay. The delay for channel 1 in this illustrativeexample is fixed while the operation of channel 2 and channel 3 aredelayed with respect to channel 1. The addresses which correspond tothese delays may be established by trial runs with the printing machinecycling at very low speed. The operator will observe the locations atwhich the machine prints and makes adjustments in the number of LSpulses which are counted as well as in the relative angular position ofthe print wheel shafts 30 with respect to the drive pucks 56, 64 and 68,as was explained in connection with FIG. 2. The first several documentnumbers and documents on which they are printed will not be usable.However, alignment and timing for high speed runs is effectively"proofed" and established for these runs.

In proper time relationship in each cycle of operation of the printingmachine, at a time slightly delayed from the lead strobe (LS), an ROSTRB(readout strobe) pulse is outputted by the input data control logic 92.This pulse is applied to the readout input of the FIFO memory 90 in theinterface 86 and to the read enable and shift inputs of the buffermemories in each of the channels 96, 98 and 100. The last data word inthe FIFO memory 90 is transferred to the input of the buffer memories ofthe channel and the words are shifted between successive stages in thebuffer memories. The output lines from the buffer memories are addressed(one set chosen for each of channel 2 and channel 3) by the delay timer104. The stepper motor control therefore receives properly timed datawords which can be printed on the staggered print heads so as to providehigh speed document number imprinting.

From the foregoing description it will be apparent that there has beenprovided an improved control system which is especially suitable for usein controlling document number imprinting machines. The system howeverhas application to the control of multiplicities of data responsivedevices of types other than check number printers, such for example asprocess controllers and tools which perform successive operations ondigitally controlled machine tools. Accordingly, the foregoingdescription should be taken merely as illustrative and not in anylimiting sense.

What is claimed is:
 1. In printing apparatus for printing a plurality ofassociated identification numbers and check digits on each of asuccession of documents where the identification numbers and associatedcheck digits on the same document are all alike but the associatedidentification numbers and check digits are changed on successivedocuments, said apparatus having a plurality of numbering devices whichare simultaneously cyclically driven synchronously with the feeding ofsaid documents into registration with said devices for printing saididentification numbers, and a plurality of number printers eachseparately associated with a different one of said numbering devices forprinting the check digits for the identification numbers associatedtherewith, a control system for said apparatus which enables theassociated identification number numbering devices and check digitnumber printers to print on different ones of said successive documents,said control system comprisingmeans driven cyclically with differentones of said identification number numbering devices for providing aplurality of first timing signals each corresponding to a different oneof said identification number numbering devices and synchronously withthe printing of each of said successive identification numbers, meansfor selecting one of said first timing signals as a lead timing signal,means interfacing with a source of data words each of which data wordsrepresents a successive one of said check digits for storing a pluralityof said data words in succession, a plurality of channels eachcorresponding to a different one of said check digit number printers,each of said channels having a separate shift register for said datawords in which said data words are stored in successive stages, and acontrol means for translating said data words into a signal foroperating said check digit number printer corresponding to said channelto present for printing check digits represented by said data words,means operated by said lead timing signal for reading out one at a timedata words from said interfacing means simultaneously into all of saidshift registers in said plurality of channels and advancing saidregisters to shift said data words to the next successive stagestherein, addressing means for reading out the words stored in selectedstages of said registers in different ones of said channels to saidcontrol means thereof, and means for enabling each of said control meansseparately with the one of said first timing signals corresponding tothe one of said identification number numbering devices associated withthe check digit number printer operated by the one of said control meanswhich is enabled.
 2. The invention as set forth in claim 1 wherein saididentification numbering devices each include a plurality of numberprinting wheels coupled to separate shafts, each of which is rotated toincrement the identification number to be printed, said first timingsignal providing means includes means for translating the rotation ofsaid shafts into separate ones of said first timing signals.
 3. Theinvention as set forth in claim 2 wherein said means for translating therotation of said shafts into separate ones of said first timing signalsincludes separate discs rotatable with each of said shafts, a magnet onsaid disc, and separate Hall effect detectors in proximity to each ofsaid discs, each for producing a separate one of said first timingsignals upon each cycle of rotation of said shafts when said magnetspass said detectors.
 4. The invention as set forth in claim 2 whereinsaid check digit number printers each include a rotatable wheel havingtype faces of successive ones of said check digits at successivepositions along the periphery thereof, a stepper motor coupled to saidwheel for rotating said wheel, and said control means being a steppermotor control which converts said data words into pulses and directionsignals corresponding to different ones of said digits.
 5. The inventionas set forth in claim 4 further comprising means coupled to said controlmeans for advancing said stepper motors independently to set said wheelsat any selected check digit.
 6. The invention as set forth in claim 1wherein said source of data words is a computer which generates saiddata words, and said interface means includes a first in-first outmemory device for storing a plurality of said data words generated insuccession by said computer.
 7. The invention as set forth in claim 6further comprising keyboard means for operating said lead timing signalselecting means and said addressing means.